The invention relates to a method of handling data in a received television signal of the MAC packet type which television signal is in time multiplexed component form the majority of the line periods of a television frame of which contain a digital data burst component and a vision component, the data burst component comprising first and second adjacent sub-components with said first and said second sub-components in each frame forming the data in respective first and second subframes which data in each subframe is organized as a packet multiplex. The invention relates to apparatus for use with the above method.
Television signals of the MAC packet type are described in the European Broadcasting Union documents SPB 284, 3rd revised version "Television Standards for the Broadcasting Satellite Service Specification of the C-MAC Packet System", December 1984 and SPB 352 "Methods of conveying C-MAC Packet Signals in Small and Large Community Antenna and Cable Network Installations, December, both of which are incorporated herein by way of reference. For the C- and D-MAC Packet systems the data is contained within two B subframes in each television frame and data relating to a particular service may be contained in one such subframe or both subframes. It is necessary for the data from both subframes to be readily available for recovery devices for the data and at the same time keep the connections necessary to a minimum especially as the formation and recovery of the packets will be performed by different integrated circuits.